Heat treatment apparatus

ABSTRACT

Apparatus which is adapted to be removed and replaced as a unit in a quench system for applying quenching fluid at high pressure to a heated workpiece with means to form a continuous uniform curtain of quenching fluid on the workpiece.

United States Patent Winkler et al.

[151 3,656,733 [451 Apr. 18, 1972 [541 HEAT TREATMENT APPARATUS /21 Inventors: Robert L. Winkler, Bethlehem, Pa.; William J. Baker, Valparaiso, Ind.

[73] Assignee: Bethlehem Steel Corporation [22] Filed: Oct. 30, 1969 [21] Appl. No.: 872,676

[52] US. Cl. ..266/6 S, 134/122 [51] Int. Cl. ...C21d l/62 [58] Field of Search ..72/20l, 202; 266/4 R, 4 S,

266/6 R, 6 S;148/12.4,143-145,l52, 153,131;

[56] References Cited UNITED STATES PATENTS 3,405,627 10/1968 Day et al ..134/122 3,420,083 l/19 69 Safiord et a1. ..72/20l 3,423,254 1/1969 Safford et a1. ..266/6 S 3,466,023 9/1969 Cunningham et a1 ..266/4 S Primary Examiner-Gerald A. Dost Anomey-Joseph J. O'Keefe [57] ABSTRACT Apparatus which is adapted to be removed and replaced as a unit in a quench system for applying quenching fluid at high pressure to a heated workpiece with means to form a continuous uniform curtain of quenching fluid on the workpiece.

- 7 Claims, 4 Drawing Figures HEAT TREATMENT APPARATUS BACKGROUND OF THE INVENTION Recent advances have been made in the heat treatment of low carbon plate to produce quenched and tempered plate having selected properties. The design of modem quenching facilities provides a quench necessary to obtain desired strength level and uniformity of properties in plate of a degree that was unobtainable until recently. A high pressure-high volume application of a precisely controlled curtain of quenching fluid is made in the initial stages of the quench in order to rapidly quench the plate followed by a low pressurehigh volume application of quenching fluid to keep the plate surface cold. The plate is kept moving through the quenching unit and held flat by opposing rollers which engage the plate therebetween.

The high pressure-high volume quench is applied by a pair of opposing units comprising entry and exit rollers with a quench fluid supply header having a nozzle discharging a quenching fluid between the rollers to impinge upon both sides of the plate under treatment with the opposing lines of impingement in vertical alignment. The nozzle of the prior art equipment comprised a plurality of spaced round orifices in the supply header with a deflector attached to the header to direct the flow as desired onto the heated plate. It is imperative that the proper angle of impingement of the quench fluid on the heated surface be maintained to guarantee uniformity in the properties of the finished plate. Some of the difficulties arising from the necessity to maintain precise control include maintaining the alignment of the deflector plate to insure a uniform quench across the plate. The adjustment is time consuming' and difficult to accomplish with accuracy. Constant adjustment is necessary because of the instability of the prior art design. It is desirable, therefore, to accomplish positive positioning of the quench units within the system initially to avoid the necessity for additional adjustment during operation of the system.

Another difiiculty arises from clogging of the relatively small round orifices from debris that isin the quench water with no means provided to satisfactorily clean the clogged orifices.

It is an object of this invention, therefore, to provide apparatus which can be accurately adjusted prior to installation and is rugged enough to maintain the adjustment through severe operation.

It is another object to provide apparatus which can be readily removed and replaced as a unit.

It is a further object of this invention to provide apparatus which minimizes the adverse effects of debris in the quenching fluid.

It is still another object of this invention to provide means for producing a relatively dense sheet of quenching fluid.

SUMMARY OF THE INVENTION The instant invention accomplishes these objects by providing ruggedly built apparatus which is adapted to be preassembled and prealigned on a test stand for rapid installation when replacement is required. The apparatus is further adapted to produce a uniform curtain of quenching fluid and to minimize clogging'of the nozzle orifices by debris found in the quench fluid by means of a unique orifice design.

BRIEF DESCRIPTION OF THE DRAWINGS I FIG. 1 is an elevational view of the invention installed in a quench stand with rolls l3 omitted for purposes of clarity;

FIG. 2 is a partial sectional view of the invention taken on line 22 of FIG. 1;

FIG. 3 is an enlarged detail view of a portion of the inventron;

FIG. 4 is a plan view taken on line 44 of FIG. 2.

Referring now to the drawings for a detailed description of the invention and particularly to FIG. 1 the apparatus is seen to generally comprise quench stand 10, manifold pipe 11 which is a source for quenching fluid, supply headers 12, rolls 13 and 13, support means 14 and 15 and nozzles 16. The upper roller platen 17 of the quench stand 10 is adapted to be moved vertically by any convenient means (not shown) as, e. g., hydraulic cylinders for the purpose of adjusting the opening between the upper and lower set of rolls to accommodate various gauges of heated workpieces 18 being treated. The vertical movement of platen 17 also permits the removal of the quench stand sub-assemblies 19 of the instant invention as will be evident as the invention is more fully described.

The sub-assembly 19 comprises a quenching fluid supply header 12 detachably connected as by bolting at flanges 20 to a source of quenching fluid. The supply header 12 is mounted on support means 14 and 15 which is in turn removably mounted on the structure of quench stand 10. A pair of spaced apart rolls 13 and 13' is mounted in pillow blocks 21 on support means 14. Nozzle 16 is removably mounted on the supply header 12 between the spaced apart rolls l3 and 13' and is adapted to direct a continuous curtain of quench fluid under high pressure at a desired angle of impingement across the surface of the heated workpiece.

The quench sub-assembly 19 is readily removed from the quench stand 10 as a unit by removing the mounting means, eg bolts, at the connecting points 14, 15, and 20. The upper platen 17 is movable vertically, as hereinbefore explained, to implement the safe and rapid removal and replacement of the unit 19 as will be readily recognized by those skilled in the art.

The nozzle 16 as seen in FIG. 2 is mounted on the header l2 communicating with a plurality of spaced holes 22 therein. Mounting plate 23 is fixedly attached to header 12 in any convenient fashion as, e.g., by welding. Box-like chamber 24 having an inlet portion 25 and discharge opening 26 is removably attached by bolts 27 to mounting plate 23. One side 28 of the box-like chamber 24 is provided with openings or orifices 29 along its edge, FIG. 4, and cooperates with an adjacent removable side 31 which, in the preferred embodiment shown, is a deflector plate having a curved end portion 32. Side or deflector plate 31 is attached to box-like chamber 24 by means of a plurality of bolts 33 and retainer disks 34 which draw the flat portion of the deflector plate tightly against the ridges of the scalloped edge 29 to form a rigid nozzle structure capable of resisting the high hydraulic pressures applied thereto. The nozzle discharge opening 26 is thus formed by the juncture of the two adjacent sides 28 and 31. Ease of flushing the box-like chamber is provided by backing off bolts 33 slightly to open up the discharge opening 26.

The edge of the discharge opening 26 has a scalloped configuration as seen in FIG. 4, formed by a series of consecutively formed curvilinear orifices 29 having a constant section through substantially the thickness of the edge.

The nature of the flow of quenching fluid, its uniformity and homogeneity, is dependent upon the shape of the discharge opening 26. One side 31 of the box-like chamber 24 forms a closure on one side of the orifices 29 providing a smooth uninterrupted guide for the discharging fluid. This flat side combined with the elongated orifices results in a curtain or quenching fluid which is of substantially uniform thickness. Prior art deflector plates in combination with round orifices produce rod-like or columnar flow of the quenching fluid resulting in streaking or non-uniform quench. In addition, turbulence is created when the rods strike the deflector which entrains excessive amounts of air in the quenching fluid decreasing the effectiveness of the quench. It has been found that the elongated shape of the curvilinear orifices 29 shown in FIG. 4 minimizes the tendency for debris, e.g. wood fibers, in the quench fluid to bridge the openings causing clogging thereof.

The quenching fluid discharges from headers 12 through a plurality of discharge openings 22 in columnar or rod-like form and is forced against shelf 37 in the box-like chamber 24 thus distributing the rod-like columns of fluid evenly throughout the header developing a uniformly pressurized chamber of fluid which is discharged under great pressure through the uniquely designed discharge opening 26. The quenching fluid thus discharged is in the form of a substantially uniform, homogeneous elongated curtain of fluid across the surface of the workpiece.

The deflector plate 31 is seen in more detail in FIG. 3 to which particular reference is now made. The juncture with side 28 is made along the flat portion of deflector plate 31. The plate 31 is curved beyond the discharge opening 26 to direct the fluid onto the surface of the workpiece. The ultimate angle of impingement is critical and is controlled by the deflector geometry. A test stand is provided for aligning the preassembled quench unit 19 and to verify this geometry. The curved portion 32 of the deflector plate 31 is made by roll forming a strip of plate into a circular curve with an included angle of about 100. The inside surface of the deflector must be reasonably smooth, as e.g. 63 microinches RMS finish, to avoid excessive turbulence. As the sub-assembly 19 is tested on the test stand the angle of impingement, back-wash, and shape of the curtain of fluid are observed. The front edge 35 of the deflector plate is machined back in small increments maintaining a sharp edge until the optimum conditions are obtained. At this point the rigid preassembled sub-assembly 19 is ready for installation in the quench stand and because of the rugged construction will maintain the desired alignment resulting in the application of the same quenching conditions to the workpiece as were established on the test stand.

The many advantages of the pre-assembled unit and its uniquely designed nozzle structure are thus clearly disclosed. For example, the shape of the curtain of quenching fluid impinging on the surface of the heated workpiece determines to a large extent the uniformity of the quench and consequently the uniformity of the desired properties across the surface of the workpiece. The shape of the curtain produced by the instant invention more nearly approximates a straight line on both leading and trailing edges of the impingement area of the fluid on the plate being treated. A slightly sinuous leading edge is noted. However, the shape of the leading edge of the contact area using prior art round and half round orifices is a very pronounced sine wave resulting in non-uniformity in quench and visible marking of the plate.

In addition, the elongated openings of the curvilinear orifices give the longest openings possible to prevent clogging or bridging by the fibrous debris in the quenching fluid while still providing adequate support for preloading the deflector. This adds to the rugged construction of the preadjusted unit and overcomes the necessity for adjustment after installation.

We claim:

1. In a pressure quench system for applying a quenching fluid to a heated workpiece, a quench stand sub-assembly comprising:

a. a support means attached to said quench stand,

b. a supply header attached to said support means having discharge openings therein,

c. detachable means for connecting said header to a source of said quenching fluid,

d. spaced apart rolls mounted on said support means, and

e. a nozzle having a discharge opening one side of which extends beyond said opening to integrally form a deflector plate to direct a substantially uniform, homogeneous curtain of said quenching fluid onto said workpiece, said nozzle mounted on said header between said spaced apart rolls and communicating with said openings in said header.

2. In a pressure quench system for applying a quenching fluid to a heated workpiece, a quench stand sub-assembly adapted to be removed and replaced as a unit, comprising:

a. support means removably attached to said quench stand,

b. a supply header attached to said support means having discharge openings therein,

c. detacha le means for connecting said header to a source of said quenching fluid,

d. spaced apart rolls mounted on said support means, and

e. a nozzle mounted on said header between said spacedapart rolls and communicating with said openings in said header comprising a box-like chamber having a discharge opening and a deflector mounted on said chamber adjacent said discharge opening to direct a continuous sheet of quenching fluid onto the surface of said workpiece.

3. Apparatus according to claim 2 wherein the discharge opening of said box-like chamber is formed by the juncture of two adjacent sides thereof.

4. Apparatus according to claim 3 wherein one edge of the discharge opening of said box-like chamber has a scalloped configuration.

5. Apparatus according to claim 3 wherein one side of the discharge opening'of said box-like chamber is a deflector plate extending beyond said juncture of said two adjacent sides.

6. Apparatus according to claim 4 wherein said scalloped edge comprises a series of consecutively formed curvilinear orifices with constant section substantially therethrough.

7. In apparatus for applying a quenching fluid to a heated workpiece, a nozzle comprising:

a. a box-like chamber connected to a source of quenching b. a discharge opening formed by the juncture of two adjacent sides of said box-like chamber,

c. a scalloped configuration on one edge of said discharge opening comprising a series of consecutively formed curvilinear orifices having a constant section substantially therethrough, and

d. a deflector plate forming the other side of said discharge opening and extending beyond said juncture of said two adjacent sides. 

1. In a pressure quench system for applying a quenching fluid to a heated workpiece, a quench stand sub-assembly comprising: a. a support means attached to said quench stand, b. a supply header attached to said support means having discharge opEnings therein, c. detachable means for connecting said header to a source of said quenching fluid, d. spaced apart rolls mounted on said support means, and e. a nozzle having a discharge opening one side of which extends beyond said opening to integrally form a deflector plate to direct a substantially uniform, homogeneous curtain of said quenching fluid onto said workpiece, said nozzle mounted on said header between said spaced apart rolls and communicating with said openings in said header.
 2. In a pressure quench system for applying a quenching fluid to a heated workpiece, a quench stand sub-assembly adapted to be removed and replaced as a unit, comprising: a. support means removably attached to said quench stand, b. a supply header attached to said support means having discharge openings therein, c. detachable means for connecting said header to a source of said quenching fluid, d. spaced apart rolls mounted on said support means, and e. a nozzle mounted on said header between said spaced apart rolls and communicating with said openings in said header comprising a box-like chamber having a discharge opening and a deflector mounted on said chamber adjacent said discharge opening to direct a continuous sheet of quenching fluid onto the surface of said workpiece.
 3. Apparatus according to claim 2 wherein the discharge opening of said box-like chamber is formed by the juncture of two adjacent sides thereof.
 4. Apparatus according to claim 3 wherein one edge of the discharge opening of said box-like chamber has a scalloped configuration.
 5. Apparatus according to claim 3 wherein one side of the discharge opening of said box-like chamber is a deflector plate extending beyond said juncture of said two adjacent sides.
 6. Apparatus according to claim 4 wherein said scalloped edge comprises a series of consecutively formed curvilinear orifices with constant section substantially therethrough.
 7. In apparatus for applying a quenching fluid to a heated workpiece, a nozzle comprising: a. a box-like chamber connected to a source of quenching fluid, b. a discharge opening formed by the juncture of two adjacent sides of said box-like chamber, c. a scalloped configuration on one edge of said discharge opening comprising a series of consecutively formed curvilinear orifices having a constant section substantially therethrough, and d. a deflector plate forming the other side of said discharge opening and extending beyond said juncture of said two adjacent sides. 